There's a very good reason why this film reminds you of "I am Legend" - both films - and "Omega Man" (starring Charleton Heston) - ultimately derive from a novel titled "I am Legend" - by Richard matheson.
https://en.wikipedia.org/wiki/I_Am_Legend_(novel)
(An aside: it always amazes me that people can utterly fail to do even the most basis research - in an era where the whole of human knowledge is literally a few mouse-clicks away.)
Don't mind me....just a pet-peeve of mine.